/library/Zend/Config/Yaml.php

<?php

/**

 * Zend Framework

 *

 * LICENSE

 *

 * This source file is subject to the new BSD license that is bundled

 * with this package in the file LICENSE.txt.

 * It is also available through the world-wide-web at this URL:

 * http://framework.zend.com/license/new-bsd

 * If you did not receive a copy of the license and are unable to

 * obtain it through the world-wide-web, please send an email

 * to license@zend.com so we can send you a copy immediately.

 *

 * @category  Zend

 * @package   Zend_Config

 * @copyright Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)

 * @license   http://framework.zend.com/license/new-bsd     New BSD License

 * @version   $Id: Yaml.php 24092 2011-05-31 02:43:28Z adamlundrigan $

 */



/**

 * @see Zend_Config

 */

require_once 'Zend/Config.php';



/**

 * YAML Adapter for Zend_Config

 *

 * @category  Zend

 * @package   Zend_Config

 * @copyright Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)

 * @license   http://framework.zend.com/license/new-bsd     New BSD License

 */

class Zend_Config_Yaml extends Zend_Config

{

    /**

     * Attribute name that indicates what section a config extends from

     */

    const EXTENDS_NAME = "_extends";



    /**

     * Whether to skip extends or not

     *

     * @var boolean

     */

    protected $_skipExtends = false;



    /**

     * What to call when we need to decode some YAML?

     *

     * @var callable

     */

    protected $_yamlDecoder = array(__CLASS__, 'decode');



    /**

     * Whether or not to ignore constants in parsed YAML

     * @var bool

     */

    protected static $_ignoreConstants = false;



    /**

     * Indicate whether parser should ignore constants or not

     *

     * @param  bool $flag

     * @return void

     */

    public static function setIgnoreConstants($flag)

    {

        self::$_ignoreConstants = (bool) $flag;

    }



    /**

     * Whether parser should ignore constants or not

     *

     * @return bool

     */

    public static function ignoreConstants()

    {

        return self::$_ignoreConstants;

    }



    /**

     * Get callback for decoding YAML

     *

     * @return callable

     */

    public function getYamlDecoder()

    {

        return $this->_yamlDecoder;

    }



    /**

     * Set callback for decoding YAML

     *

     * @param  callable $yamlDecoder the decoder to set

     * @return Zend_Config_Yaml

     */

    public function setYamlDecoder($yamlDecoder)

    {

        if (!is_callable($yamlDecoder)) {

            require_once 'Zend/Config/Exception.php';

            throw new Zend_Config_Exception('Invalid parameter to setYamlDecoder() - must be callable');

        }



        $this->_yamlDecoder = $yamlDecoder;

        return $this;

    }



    /**

     * Loads the section $section from the config file encoded as YAML

     *

     * Sections are defined as properties of the main object

     *

     * In order to extend another section, a section defines the "_extends"

     * property having a value of the section name from which the extending

     * section inherits values.

     *

     * Note that the keys in $section will override any keys of the same

     * name in the sections that have been included via "_extends".

     *

     * Options may include:

     * - allow_modifications: whether or not the config object is mutable

     * - skip_extends: whether or not to skip processing of parent configuration

     * - yaml_decoder: a callback to use to decode the Yaml source

     *

     * @param  string        $yaml     YAML file to process

     * @param  mixed         $section  Section to process

     * @param  array|boolean $options 

     */

    public function __construct($yaml, $section = null, $options = false)

    {

        if (empty($yaml)) {

            require_once 'Zend/Config/Exception.php';

            throw new Zend_Config_Exception('Filename is not set');

        }



        $ignoreConstants    = $staticIgnoreConstants = self::ignoreConstants();

        $allowModifications = false;

        if (is_bool($options)) {

            $allowModifications = $options;

        } elseif (is_array($options)) {

            foreach ($options as $key => $value) {

                switch (strtolower($key)) {

                    case 'allow_modifications':

                    case 'allowmodifications':

                        $allowModifications = (bool) $value;

                        break;

                    case 'skip_extends':

                    case 'skipextends':

                        $this->_skipExtends = (bool) $value;

                        break;

                    case 'ignore_constants':

                    case 'ignoreconstants':

                        $ignoreConstants = (bool) $value;

                        break;

                    case 'yaml_decoder':

                    case 'yamldecoder':

                        $this->setYamlDecoder($value);

                        break;

                    default:

                        break;

                }

            }

        }



        // Suppress warnings and errors while loading file

        set_error_handler(array($this, '_loadFileErrorHandler'));

        $yaml = file_get_contents($yaml);

        restore_error_handler();



        // Check if there was a error while loading file

        if ($this->_loadFileErrorStr !== null) {

            require_once 'Zend/Config/Exception.php';

            throw new Zend_Config_Exception($this->_loadFileErrorStr);

        }



        // Override static value for ignore_constants if provided in $options

        self::setIgnoreConstants($ignoreConstants);



        // Parse YAML

        $config = call_user_func($this->getYamlDecoder(), $yaml);



        // Reset original static state of ignore_constants

        self::setIgnoreConstants($staticIgnoreConstants);



        if (null === $config) {

            // decode failed

            require_once 'Zend/Config/Exception.php';

            throw new Zend_Config_Exception("Error parsing YAML data");

        }



        if (null === $section) {

            $dataArray = array();

            foreach ($config as $sectionName => $sectionData) {

                $dataArray[$sectionName] = $this->_processExtends($config, $sectionName);

            }

            parent::__construct($dataArray, $allowModifications);

        } elseif (is_array($section)) {

            $dataArray = array();

            foreach ($section as $sectionName) {

                if (!isset($config[$sectionName])) {

                    require_once 'Zend/Config/Exception.php';

                    throw new Zend_Config_Exception(sprintf('Section "%s" cannot be found', $section));

                }



                $dataArray = array_merge($this->_processExtends($config, $sectionName), $dataArray);

            }

            parent::__construct($dataArray, $allowModifications);

        } else {

            if (!isset($config[$section])) {

                require_once 'Zend/Config/Exception.php';

                throw new Zend_Config_Exception(sprintf('Section "%s" cannot be found', $section));

            }



            $dataArray = $this->_processExtends($config, $section);

            if (!is_array($dataArray)) {

                // Section in the yaml data contains just one top level string

                $dataArray = array($section => $dataArray);

            }

            parent::__construct($dataArray, $allowModifications);

        }



        $this->_loadedSection = $section;

    }



    /**

     * Helper function to process each element in the section and handle

     * the "_extends" inheritance attribute.

     *

     * @param  array            $data Data array to process

     * @param  string           $section Section to process

     * @param  array            $config  Configuration which was parsed yet

     * @return array

     * @throws Zend_Config_Exception When $section cannot be found

     */

    protected function _processExtends(array $data, $section, array $config = array())

    {

        if (!isset($data[$section])) {

            require_once 'Zend/Config/Exception.php';

            throw new Zend_Config_Exception(sprintf('Section "%s" cannot be found', $section));

        }



        $thisSection  = $data[$section];



        if (is_array($thisSection) && isset($thisSection[self::EXTENDS_NAME])) {

            $this->_assertValidExtend($section, $thisSection[self::EXTENDS_NAME]);



            if (!$this->_skipExtends) {

                $config = $this->_processExtends($data, $thisSection[self::EXTENDS_NAME], $config);

            }

            unset($thisSection[self::EXTENDS_NAME]);

        }



        $config = $this->_arrayMergeRecursive($config, $thisSection);



        return $config;

    }



    /**

     * Very dumb YAML parser

     *

     * Until we have Zend_Yaml...

     *

     * @param  string $yaml YAML source

     * @return array Decoded data

     */

    public static function decode($yaml)

    {

        $lines = explode("\n", $yaml);

        reset($lines);

        return self::_decodeYaml(0, $lines);

    }



    /**

     * Service function to decode YAML

     *

     * @param  int $currentIndent Current indent level

     * @param  array $lines  YAML lines

     * @return array|string

     */

    protected static function _decodeYaml($currentIndent, &$lines)

    {

        $config   = array();

        $inIndent = false;

        while (list($n, $line) = each($lines)) {

            $lineno = $n + 1;

            

            $line = rtrim(preg_replace("/#.*$/", "", $line));

            if (strlen($line) == 0) {

                continue;

            }



            $indent = strspn($line, " ");



            // line without the spaces

            $line = trim($line);

            if (strlen($line) == 0) {

                continue;

            }



            if ($indent < $currentIndent) {

                // this level is done

                prev($lines);

                return $config;

            }



            if (!$inIndent) {

                $currentIndent = $indent;

                $inIndent      = true;

            }



            if (preg_match("/(\w+):\s*(.*)/", $line, $m)) {

                // key: value

                if (strlen($m[2])) {

                    // simple key: value

                    $value = rtrim(preg_replace("/#.*$/", "", $m[2]));

                    // Check for booleans and constants

                    if (preg_match('/^(t(rue)?|on|y(es)?)$/i', $value)) {

                        $value = true;

                    } elseif (preg_match('/^(f(alse)?|off|n(o)?)$/i', $value)) {

                        $value = false;

                    } elseif (!self::$_ignoreConstants) {

                        // test for constants

                        $value = self::_replaceConstants($value);

                    }

                } else {

                    // key: and then values on new lines

                    $value = self::_decodeYaml($currentIndent + 1, $lines);

                    if (is_array($value) && !count($value)) {

                        $value = "";

                    }

                }

                $config[$m[1]] = $value;

            } elseif ($line[0] == "-") {

                // item in the list:

                // - FOO

                if (strlen($line) > 2) {

                    $config[] = substr($line, 2);

                } else {

                    $config[] = self::_decodeYaml($currentIndent + 1, $lines);

                }

            } else {

                require_once 'Zend/Config/Exception.php';

                throw new Zend_Config_Exception(sprintf(

                    'Error parsing YAML at line %d - unsupported syntax: "%s"',

                    $lineno, $line

                ));

            }

        }

        return $config;

    }



    /**

     * Replace any constants referenced in a string with their values

     *

     * @param  string $value

     * @return string

     */

    protected static function _replaceConstants($value)

    {

        foreach (self::_getConstants() as $constant) {

            if (strstr($value, $constant)) {

                $value = str_replace($constant, constant($constant), $value);

            }

        }

        return $value;

    }



    /**

     * Get (reverse) sorted list of defined constant names

     *

     * @return array

     */

    protected static function _getConstants()

    {

        $constants = array_keys(get_defined_constants());

        rsort($constants, SORT_STRING);

        return $constants;

    }

}